Molecular detection of human enteric viruses circulating among children with acute gastroenteritis in Valencia, Venezuela, before rotavirus vaccine implementation

Abstract

BackgroundThe role of rotavirus as main etiologic agent of diarrhea has been well documented worldwide, including in Venezuela. However, information about the prevalence of gastrointestinal viruses such as calicivirus, adenovirus and astrovirus is limited and the contribution of other agents as Aichi virus and klassevirus is largely unknown. To explore the etiological spectrum of diarrhea associated with agents other than rotaviruses, 227 stool samples from children under 5 years old with acute gastroenteritis, collected in Valencia (Venezuela) from 2001 to 2005, and previously tested as rotavirus-negative, were analyzed for caliciviruses, adenoviruses, astroviruses, Aichi viruses, klasseviruses, picobirnaviruses and enteroviruses by specific RT-PCRs.ResultsAt least one viral agent was detected in 134 (59%) of the samples analyzed, mainly from children under 24 months of age and most of them belonging to the lowest socioeconomic status. Overall, enterovirus was identified as the most common viral agent (37.9%), followed by calicivirus (23.3%), adenovirus (11.5%), astrovirus (3.5%), klassevirus (1.3%) and Aichi virus (0.4%), while no picobirnavirus was detected. Klasseviruses were found during 2004 and 2005 and Aichi viruses only in 2005, indicating their circulation in Venezuela; meanwhile, the rest of the viruses were detected during the whole study period. Coinfections with two or more viruses were found in 39 (29.1%) of the infected children, most under 24 months of age. Adenovirus was involved as the coinfecting agent in at least 46.9% of the cases, but no differences concerning socio-demographic variables were observed between the coinfected and the single infected children.ConclusionsThe results show that various enteric viruses, including enteroviruses, caliciviruses and adenoviruses, accounted for a significant proportion of infantile diarrhea cases in Venezuela before rotavirus vaccine implementation. In addition, emerging viruses as Aichi virus and klassevirus were found, indicating the need to continue monitoring their spreading into the communities. Efforts are needed to develop more accurate methods to identify the major causes of diarrhea and to provide tools for more effective preventive measures.

Human Enteric Circulating Viruses and Co-infections Among Hospitalized Children with Severe Acute Gastroenteritis in Chihuahua, Mexico, During 2010 - 2011

“…In the present study, adenovirus, astrovirus, and norovirus co-infections with rotavirus were determined. Our results indicated that, unlike other studies, only was rotavirus found co-infecting with other enteroviruses, where no co-infection between adenovirus, astrovirus, and norovirus was detected, whereas reports from South America indicated viral co-infections in samples from patients diagnosed with AGE (2,43,44). In summary, co-infections between enteric viruses are increasing, which represents a serious problem for human health due to the emergence of these viruses in children under fiveyears-old (2, 27, 43-45).…”

“…Among enterovirus-positive samples, the highest incidence was related to rotavirus, followed by adenovirus, indicating differences from the incidence of enteric viruses worldwide, in which the norovirus incidence was second after that of rotavirus (21,22). Viral co-infections were detected in 14% of the analyzed samples, where rotavirus was detected coinfecting with other detected enteroviruses (2).…”

“…Viruses from four families Reoviridae (group A rotavirus), Caliciviridae (norovirus), Adenoviridae (adenovirus, mainly serotype 40/41, coded as species F), and Astroviridae (astrovirus) are considered major causal agents of acute diarrhea among children. Among them, rotavirus is considered the predominant disease agent (2). Since 2006, when vaccination against rotavirus was implemented in several Latin-American countries, other enterovirus family species, such as norovirus, adenovirus, and astrovirus, have greatly increased compared to previous years (3).…”

“…For example, after implementation of the rotavirus vaccine in 2006, caliciviruses were mostly begun to detect in association with gastroenteritis symptoms, followed by adenovirus, which was listed as the second or third diarrhea-causing viral agent, whereas astrovirus was predominantly observed among children up to two years of age showing severe gastrointestinal problems (2,7,8). These new findings reveal the lack of detailed information regarding the prevalence of enteroviruses associated with severe acute gastroenteritis.…”

Analysis of viral diversity in stool samples from infants and children with acute gastroenteritis in Kuwait using Metagenomics approach

“…Adenoviruses were detected as co-infection viruses in 20.9% (9/43) of the positive samples. According to several studies conducted in Korea, Japan, Albania, and Venezuela, mixed infections of enteric and non-enteric adenoviruses are common and might play a role in acute gastroenteritis [39][40][41][42][43]. The clinical importance of mixed viral infection is an unresolved question.…”